Multiple rudder and skeg arrangement for single screw vessels



; Filed July 12, 1946- 3 Sheets-Sheet 1 June 12, 1951 A. DE HAAN 2,556,320

MULTIPLE RUDDER AND SKEG ARRANGEMENT FOR smsua: SCREW .VESSELS 1N VEN TOR.

June 12, 1951 A, DE HAAN MULTIPLE RUDDER AND- SKEG ARRANGEMENT FOR smcuz SCREW VESSELS SSheets-Sheet 2 Filed July 12, 1946 INVENTOR.

N A A H E D A June 12, 1951 'A. DE HAAN 7 2,556,320

' MULTIPLE RUDDER AND SKEG ARRANGEMENT FOR SINGLE SCREW VESSELS Filed July 12, 1946 3 Sheets-Sheet 3 IN V EN TOR.

A. DEHA a 8 I 2 N, A-rrrwa Patented June 12, 1951 MULTIPLE RUDDER AND s Ee ARRANGE- MENT FOR SINGLE SQREW VESSE r n de Haa sden o h Macs, Netherlands Application July 12, 1946, Serial No. 683,027 n h et erla ds anuary 1 Section 1, Public Law 691), August 8, 1946, Patent expires January 23, 1959 3 'Qlaims.

The present invention relates to a multiple rudder and skeg arrangement for single screw vessels.

More particularly the invention relates to the fore-going arrangement in combination with a particular hull contour generally referred to by the term cruiser stern but specifically denoting a contour which in side elevation presents a hull line upwardly curved from the keel in a gentle longitudinal curve toward the stern and terminating in a substantially vertical stern and which in the area of the stern in rear end elevation presents upward curvatures from the keel line, to .a greater degree of curvature than the aforementioned longitudinal curvature so as to provide a transverse cross section in which the contour lines transversely of the vessel meet in the area of the stern, while forming an obtuse angle.

The invention, therefore, has for an object to improve the steering or maneuverability of a vessel with the above noted hull characteristics.

An additional object is to, while improving the maneuverability, also obtain an increased propeller efilciency utilizing a single screw or propeller.

A specific object is to provide an arrangement embodying laterally spaced skegs on opposite sides of the propeller and generally parallel with the propeller axis and two balanced rudders each pivoted rearwardly of the skegs so that the rudders and the skegs cooperate to providea tunnel to increase the propulsive effect of the screw.

A further object is to provide a bearing surface on each skeg for supporting each of the rudder posts or shafts.

A further object is to provide a curved plate in combination with the afore-mentioned structure that extends from the rearward edges of the skegs forwardly and merges with the hull forwardly of the propeller and which tunnel plate does not completely encompass the propeller.

Further and more specific objects will be apparent from the accompanying drawings in which Figure l is a longitudinal section through the poop of a vessel;

Figure 2 is a horizontal section through the poop of the vessel;

Figure 3 is a cross section through the poop of the vessel at the heighth of the engine room;

Figure 4 is a partial rear end elevation, partial section View with the rudders removed; and

Figure 5 is a diagram of the frame members.

With respect to the drawings, in vessels, particularly river and canal craft, the poop generally serves for living quarters and for ballast tanks (Cl; 1 1 4, 57) r 2 and in the embodiment illustrated the engine room is likewise located in the poop. Therefore the upper space of the poop is denoted by the reference character 3, the helmsmans space by l a; and reference numeral Q denotes a water ballast tank. The remainder of the space toward the front of the vessel encompasses a cargo hold denoted at H.

Figure l, the engine [3 has extending therefrom a propeller shaft I i passing through a suitable propeller tube 59 and receiving the screw or propeller 2|.

As indicated in the drawings, the hull contour line of the-vessel shows, in Figure 1, a gentle longitudinal curve upwa y fr m th l lin t and terminating in a substantially vertical stern. In Figure 4 it is noted that in the area .ad'acent the stern the sides of the hull curve updly from the keel line through a greater degree e f curvature than the longitudinal rearward rarrvature mentioned above and thereby providing a transverse hull cross section in which the contour lines transversely of the vessel meet'while fern -ing an obtuse angle.

The propeller 2| is mounted substantially on lthe keel line forwardly of the vertical stern and in spaced relation rearwardly of the upwardly curved longitudinal hull profile thereby providing an open area forwardly of the propeller for :passage of water. It is readily understood that water can pass beneath the rear area of the vess el orwardly of the propeller. On each sideof .1} propeller there are provided skegs 23 each extending vertically beneath the hull and spaced apartto provide a water passage so that the water can he guided to the propeller. These skegs are-figedandareof narrow fore and aft dimensions and extend longitudinally of the vessel. l he skegs are of greater fore and aft dimensions than the fore and aft dimensions of the propeller :and they are transversely aligned with the propeller-so that the propeller is positioned between them and partially housed thereby. It is iurther clear from Figure 1 that the forward edge of the skeg terminates in spaced relation tothe hull so ,as not to obstruct the flow of water transversely loeneatl i the curved hull contour toward the .propeller. In addition each skeg is provided with a rearward extension from the lower rear edge thereof terminating in a support or heel 2-1 sup-- porting rudder posts 33 and 34.which, as shown, .passthrough rudders -,2 8 and 29. This arrange- ;-ment minimizes damage to the rudders in the v t the vessel 1 11 5 aground. In connection 5.5 therudders, it is noted that theiraxes are equidistant from the keel line and rearwardly of 'shaft 44 and the gearing 43, 42, 4|, 39, 38, 31 to the propeller. In addition the rudder posts 33 and 34 pass through the rudders rearwardly of the forward edges thereof and which forward edges of the rudders are, when the rudders are in parallelism with the propeller axis, closely adjacent the rear edges of the skegs so that the skegs together with the rudders provide a tunnel effect to increase the propulsive effect of the propeller when the ship is moving ahead. When the ship is being maneuvered or turned the area of the rudders between the axes provided by the rudder posts 33 and 34 cooperates with the skegs and the space between the forward edges of the skegs and the hull so that an opening is provided for side entry of Water between the rudder and skeg on the leading side of the vessel in accordance with its direction of turning and further the water can slip beneath the hull forwardly of the propeller, and water from the propeller can exert force on the opposite rudder, that is the trailing rudder, in the direction of turning, on that area between the rudder post and the forward edge of the rudder so that these combined effects, at least partially disrupt the water jet issuing from between the rudders. In this connection, it is well known that a tunnel such as provided by the skegs and rudders or a kort tunnel provided on vessels occasions the existence of a water jet issuing outwardly of the vessel thereby increasing the propulsive effect of the propeller disposed within the tunnel. However, a compact propeller jet that is delivered by a propeller, due to the large quantity of energy required for effecting a change in its direction in order to bring the water particles thereof into the whirl, acts in a manner similar to a skeg extending rearwardly of the Vessel. This feature will further assist in the stabiliza tion of the course of the vessel but it will deleteriously exert drag action when attempting to maneuver or turn the vessel. Therefore the present arrangement while providing, through the disposition of the skegs and rudders, an increased propeller efficiency also provides an arrangement which as soon as the helm is turned the water jet is dispersed due to the opening of the slots between the rudders and skegs through which water can flow off laterally of the propeller axis.

As indicated in Figure 4, the stern of the vessel provided with a tunnel plate 3| which extends from an area adjacent the rear edge of the skegs towards and contacts the outer skin or hull of the vessel. The dotted line 32 in Figure 1 denotes the area of contact with the hull. It is thus'seen that the propeller is still not completely "surrounded or enclosed in a manner similar to a 'kort nozzle arrangement. The tunnel plate 3| is of an advantage when backing a vessel in shallow water since the propeller will be sufficiently "provided with water. In Figure 4, the dotted line 36 denotes the draft of the vessel when the same is empty.

As stated, the rudders 28 and 29 are provided with the rudder posts 33 and 34, which have keyed thereon quadrants 31 and 38, respectively. The

the helm or wheel 48 is transmitted through the rudders.

It is thereby clear that I have provided an arrangement which is ideally suited for river craft or barges, particularly those of considerable length with respect to their breadth. As a practical embodiment of the invention, it has been demonstrated that it is possible utilizing the structure of this invention to turn a 1000 ton barge having a length of 6'7 meters and a width of 8.2 meters which was lying head on in a stream and was not moored to a wharf, that is the craft was not connected in any way with the shore, about the fore most part of the stem. It was also further demonstrated that this barge lying unmoored in a river turned about her median axis while remaining in the same place during this maneuver.

' What I claim is:

1. In combination with a vessel having a hull contour in side elevation upwardly curved from the keel in a gentle longitudinal curve toward the stern and terminating in a substantially vertical stern and in rear end elevation in the area adjacent the stern curving upwardly from the keel line through a greater degree of curvature than the afore-mentioned longitudinal curvature to provide a transverse cross section in which the contour lines transversely of the vessel meet while forming an obtuse angle, a propeller mounted on the keel line forwardly of the vertical stern and in spaced relation rearwardly of the upwardly curved longitudinal hull profile thereby providing an open area forwardly of the propeller for passage of water, a pair of rudders wardly of the forward edges thereof, a pair of fixed skegs of narrow fore and aft dimensions extending vertically beneath the hull and longitudinally of the vessel in respective alignment with the vertical longitudinal planes containing the rudder axes and of fore and aft dimensions in excess of the fore and aft dimensions of the propeller and in transverse alignment with the propeller whereby the propeller is positioned between and partially housed by the skegs, said skegs including forward edges adjacent the hull keel terminating in spaced relation with respect to the upwardly curved hull contour and thereby providing unobstructed flow of water transversely beneath the curved hull contour toward the propeller and the skegs further including rear edges adjacent the said forward edges of the rudders so that the skegs together with the rudders provide a tunnel effect to increase the propulsive effect of the propeller when the ship is moving ahead and the area of the rudders forward of the axes thereof cooperating with the skegs and the space between the forward edges of the skegs and the hull so that in maneuvering the vessel an opening is provided between each rear edge of the skegs and the adjacent rudder axis to permit side entry of water into the space between the rudders to at least partially disrupt the jet issuing from between the rudders to reduce rag action of the water jet issuing outwardly of the vessel to thereby increase the maneuverability characteristics of the vessel.

2. The combination as defined in and by claim 1 in which rudder shafts are provided extending "through the rudders along said axes and a support pivotally engaging each shaft is carried by the lower portion of the rear side of each skeg.

3. The combination as defined in and by claim 1 and a curved tunnel plate mounted between the skegs and over the propeller and extending forwardly from adjacent the rear sides of the skegs and merging with the hull forwardly of the propeller.

ADRIAAN DE HAAN.

, REFERENCES CITED The following references are of record in the file of this patent:

Number Number 6 UNITED STATES PATENTS Name Date Montgomery Mar. 1, 1859 Macpherson June 25, 1872 Hitzler Aug. 16, 1932 FOREIGN PATENTS Country Date Germany Oct. 9, 1884 Germany Sept. 10, 1936 France Mar. 11, 1930 

